The DropShadowFilter class lets you add a drop shadow to display objects.
The shadow algorithm is based on the same box filter that the blur filter uses. You have
several options for the style of the drop shadow, including inner or outer shadow and knockout mode.
You can apply the filter to any display object (that is, objects that inherit from the DisplayObject class),
such as MovieClip, SimpleButton, TextField, and Video objects, as well as to BitmapData objects.
The use of filters depends on the object to which you apply the filter:
To apply filters to display objects use the
filters property (inherited from DisplayObject). Setting the filters
property of an object does not modify the object, and you can remove the filter by clearing the
filters property.
To apply filters to BitmapData objects, use the BitmapData.applyFilter() method.
Calling applyFilter() on a BitmapData object takes the source BitmapData object
and the filter object and generates a filtered image as a result.
If you apply a filter to a display object, the value of the cacheAsBitmap property of the
display object is set to true. If you clear all filters, the original value of
cacheAsBitmap is restored.
This filter supports Stage scaling. However, it does not support general scaling, rotation, and
skewing. If the object itself is scaled (if scaleX and scaleY are
set to a value other than 1.0), the filter is not scaled. It is scaled only when
the user zooms in on the Stage.
A filter is not applied if the resulting image exceeds the maximum dimensions.
In AIR 1.5 and Flash Player 10, the maximum is 8,191 pixels in width or height,
and the total number of pixels cannot exceed 16,777,215 pixels. (So, if an image is 8,191 pixels
wide, it can only be 2,048 pixels high.)
If, for example, you zoom in on a large movie clip with a filter applied, the filter is
turned off if the resulting image exceeds the maximum dimensions.
The alpha transparency value for the color. Valid values are 0 to 1.
For example, .25 sets a transparency value of 25%.
The default value is 1.
Implementation public function get alpha():Number public function set alpha(value:Number):void
angle
property
angle:Number
Language Version :
ActionScript 3.0
Product Version :
Flex 4
Runtime Versions :
Flash Player 10, AIR 1.5
The angle of the bevel. Valid values are from 0 to 360°.
The angle value represents the angle of the theoretical light source falling on the
object and determines the placement of the effect relative to the object.
If the distance property is set to 0, the effect is not offset from the object and,
therefore, the angle property has no effect.
The default value is 45.
Implementation public function get angle():Number public function set angle(value:Number):void
color
property
color:uint
Language Version :
ActionScript 3.0
Product Version :
Flex 4
Runtime Versions :
Flash Player 10, AIR 1.5
The color of the glow. Valid values are in the hexadecimal format
0xRRGGBB.
The default value is 0xFF0000.
Implementation public function get color():uint public function set color(value:uint):void
distance
property
distance:Number
Language Version :
ActionScript 3.0
Product Version :
Flex 4
Runtime Versions :
Flash Player 10, AIR 1.5
The offset distance of the bevel. Valid values are in pixels (floating point).
The default value is 4.
Implementation public function get distance():Number public function set distance(value:Number):void
hideObject
property
hideObject:Boolean
Language Version :
ActionScript 3.0
Product Version :
Flex 4
Runtime Versions :
Flash Player 10, AIR 1.5
Indicates whether or not the object is hidden.
The value true indicates that the
object itself is not drawn; only the shadow is visible.
The default is false, meaning that the object is shown.
The default value is false.
Implementation public function get hideObject():Boolean public function set hideObject(value:Boolean):void
inner
property
inner:Boolean
Language Version :
ActionScript 3.0
Product Version :
Flex 4
Runtime Versions :
Flash Player 10, AIR 1.5
Specifies whether the glow is an inner glow.
The value true indicates an inner glow.
The default is false that creates an outer glow
(a glow around the outer edges of the object).
The default value is false.
Implementation public function get inner():Boolean public function set inner(value:Boolean):void
distance:Number (default = 4.0) — Offset distance for the shadow, in pixels.
angle:Number (default = 45) — Angle of the shadow, 0 to 360 degrees (floating point).
color:uint (default = 0) — Color of the shadow, in hexadecimal format
0xRRGGBB. The default value is 0x000000.
alpha:Number (default = 1.0) — Alpha transparency value for the shadow color. Valid values are 0.0 to 1.0.
For example, .25 sets a transparency value of 25%.
blurX:Number (default = 4.0) — Amount of horizontal blur. Valid values are 0 to 255.0 (floating point).
blurY:Number (default = 4.0) — Amount of vertical blur. Valid values are 0 to 255.0 (floating point).
strength:Number (default = 1.0) — The strength of the imprint or spread. The higher the value,
the more color is imprinted and the stronger the contrast between the shadow and the background.
Valid values are 0 to 255.0.
quality:int (default = 1) — The number of times to apply the filter. Use the BitmapFilterQuality constants:
BitmapFilterQuality.LOW
BitmapFilterQuality.MEDIUM
BitmapFilterQuality.HIGH
For more information about these values, see the quality property description.
inner:Boolean (default = false) — Indicates whether or not the shadow is an inner shadow. A value of true specifies
an inner shadow. A value of false specifies an outer shadow (a
shadow around the outer edges of the object).
knockout:Boolean (default = false) — Applies a knockout effect (true), which effectively
makes the object's fill transparent and reveals the background color of the document.
hideObject:Boolean (default = false) — Indicates whether or not the object is hidden. A value of true
indicates that the object itself is not drawn; only the shadow is visible.
See also
flash.filters.BitmapFilterQuality
Method Detail
clone
()
method
public function clone():BitmapFilter
Language Version :
ActionScript 3.0
Product Version :
Flex 4
Runtime Versions :
Flash Player 10, AIR 1.5
Returns a copy of this filter object.
Returns
BitmapFilter — A new DropShadowFilter instance with all the
properties of the original DropShadowFilter instance.
Examples
DropShadowFilterExample.mxml
<?xml version="1.0"?>
<!--
Licensed to the Apache Software Foundation (ASF) under one or more
contributor license agreements. See the NOTICE file distributed with
this work for additional information regarding copyright ownership.
The ASF licenses this file to You under the Apache License, Version 2.0
(the "License"); you may not use this file except in compliance with
the License. You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
-->
<!-- filters/examples/DropShadowFilterExample.mxml -->
<s:Application
xmlns:fx="http://ns.adobe.com/mxml/2009"
xmlns:mx="library://ns.adobe.com/flex/mx"
xmlns:s="library://ns.adobe.com/flex/spark"
creationComplete="createFilters()">
<fx:Script><![CDATA[
import spark.filters.*;
import flash.filters.BitmapFilterQuality;
import flash.filters.BitmapFilterType;
private var myDropShadowFilter:DropShadowFilter;
private var color:Number = 0xFF33FF;
public function createFilters():void {
myDropShadowFilter = new DropShadowFilter(15, 45,
color, 0.8, 8, 8, 0.65, BitmapFilterQuality.MEDIUM, false, false);
b1.filters = [myDropShadowFilter];
}
]]></fx:Script>
<s:VGroup>
<!-- This button has a filter applied in ActionScript. -->
<s:Button id="b1" label="Click me"/>
<!-- This button has a filter applied in MXML. -->
<s:Button id="b2" label="Click me">
<s:filters>
<s:DropShadowFilter
distance="15"
angle="45"
color="0xFF33FF"
alpha=".8"
blurX="8"
blurY="8"
strength=".65"
quality="{BitmapFilterQuality.MEDIUM}"
inner="false"
knockout="false"/>
</s:filters>
</s:Button>
</s:VGroup>
</s:Application>
BaseDimensionFilter 
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